Segmented instrument having braking capabilities

ABSTRACT

A medical instrument may comprise a plurality of links disposed in series along an axial direction. The plurality of links also may comprise a brake assembly comprise one or more first braking components coupled to a first link in the pair of adjacent links and one or more second braking components coupled to a second link in the pair of adjacent links. The one or more first braking components and the one or more second braking components may have an interleaved arrangement with each other. The braking assembly may be actuatable between an engaged state and a disengaged state, wherein the one or more first braking components and the one or more second braking components inhibit the pair of adjacent links from pivoting relative to one another in the engaged state of the brake assembly, and wherein the one or more first braking components and the one or more second braking components permit the pair of adjacent links pivoting relative to one another in the disengaged state of the brake assembly. The one or more first braking components and the one or more second braking components may be pressed together in the engaged state of the brake assembly.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. application Ser.No. 12/866,309, filed Oct. 21, 2010, which is a national stageapplication of International Application No. PCT/US2009/033446, filedFeb. 6, 2009; entitled “A Segmented Instrumented Having BrakingCapabilities”, which claims the benefit of U.S. Provisional PatentApplication No. 61/026,628, filed Feb. 6, 2008, entitled “Vacuum LockTechnology” (now expired). The entire contents of each of theaforementioned applications being

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

FIELD OF THE INVENTION

Embodiments of the present invention provide articulating and lockablesegmented instruments useful in perform surgical procedures in the body.The instruments described herein may articulate and then be locked intoa desired configuration. In addition, there are also embodiments of thebrake assemblies that provide articulation capabilities when not engagedand locking capabilities when engaged.

INTRODUCTION

Guide tubes may be used to support instruments disposed within them.Many conventional guide tubes provide some form of locking capability.However, conventional guide tubes provide a single surface lockengagement when locking. Such locking configurations may provide lockingforces up to a point but are generally limited in the amount of lockingforce that may be generated. Some emerging forms of surgery may benefitfrom guide tubes or controllable instruments with locking or brakingcapabilities that provide not only improved articulation and control butalso increased locking force.

SUMMARY

Embodiments of the present invention may be useful while performingprocedures within a patient, such as in natural orifice transluminalendoscopic surgical procedures, to provide a stable controllable and/orsemi-rigid platform from which to perform the procedure. In contrast toconventional locking approaches, embodiments of the inventions describedherein provide additional frictional surfaces or in some embodimentsmultiplied frictional surfaces between articulating components. Theadditional frictional force in turn increases the braking or lockingforce applied to the instrument. Various embodiments of the presentinvention provide mechanisms by which the user can selectively rigidizeall or a portion of the elongate body through the use of multiplesurfaces placed between articulating segments or individual links orvertebra. In addition, while the braking assemblies described hereinprovide multiplied friction and lock force, they remain capable ofarticulation when not engaged. In some embodiments, the brake assemblyincludes the hinge or portion of a hinge or joint used for thearticulation of the segmented instrument.

In one aspect, there is provided a segmented instrument having aplurality of links and at least one lockable and articulatable jointpositioned to connect a pair of adjacent links in the plurality oflinks. In addition, the at least one lockable and articulatable jointbeing adapted and configured to increase the number of frictionalsurfaces available between the pair of adjacent links. As describedabove, cables and coil pipes take up a large amount of space along theelongate body. In one aspect, the brake assembly lies on or in theexterior surface of the segment, hinge or vertebra in order to keep theinterior portions of the instrument free.

In one embodiment of the present invention, there is a segmentedinstrument having braking capabilities. The instrument includes anelongate body having a plurality of links. The instrument may beconfigured as any of a wide variety of surgical devices. For example,the instrument may be an endoscope or other controllable instrument asdescribed above or it may be a guide used to direct the movement orplacement of another instrument including another segmented instrument.A hinge connects a pair of adjacent links in the plurality of links.There is a brake assembly coupled to each link in the pair of adjacentlinks. The brake assembly is positioned to span the distance between thepair of adjacent links.

A variety of different materials may be employed from which to makecomponents in a brake assembly. The desired properties of the materialsused in a brake assembly include lubricity between layers when the brakeis not actuated (e.g., braking force is not applied or no vacuum ispulled) and sufficient friction to bind the components or brake assemblywhen the brake is actuated (e.g., the braking force is applied or avacuum is pulled). Another useful property is that the brake assemblyhas the flexibility to bend when a joint is articulated. Exemplarymaterials for use in brake assembly components include, withoutlimitation, aluminum, carbon fiber, and various plastics such as andwithout limitation Teflon®.

The brake assembly may be on all or only some of the links, vertebra orsegments of an instrument. The brake assembly or multiple brakeassemblies may be placed in isolated or only specific portions of theinstrument. Numerous actuation mechanisms may be used to engage thebrake assembly or assemblies. In one aspect, the brake assemblies areactivated by pulling a cable running through or along the instrument. Inanother alternative form of activation, the interior of the scope (anormally sealed environment) is pumped down so that the interior isunder vacuum. The action of the skin of the instrument being pulled inby the vacuum may be used to actuate a braking mechanism. In addition,the brake assemblies may be activated serially or simultaneously or inany order depending upon circumstances in use. The brake assembly orassemblies may be provided only in a distal portion of the links in theplurality of links. Alternatively, the brake assembly is provided onlyin a proximal portion of the links in the plurality of links. In stillanother alternative, the brake assembly is provided only in a middleportion of the links in the plurality of links.

The movement of the pair of adjacent links about the hinge is preventedwhen the brake assembly is engaged. In one aspect, the brake assembly isprovided only between a portion of the links in the plurality of links.There are configurations of the braking assembly where one or more areplaced wherein the actuation of the brake assembly removes one degree offreedom from a portion of the instrument. In other aspects, a pluralityof brake assemblies are coupled to the instrument. In this example, theactuation of the plurality of brake assemblies substantially locks theshape of instrument by locking substantially all of the plurality oflinks in the instrument. In an alternative configuration, the pluralityof brake assemblies are coupled to the instrument wherein actuation ofthe plurality of brake assemblies substantially removes one degree offreedom from the movement of the segmented instrument.

In addition, the brake assembly is adapted and configured to complementthe operation of the hinge so that the hinge remains articulatable whenthe brake assembly is not actuated or engaged. The brake assembly isadapted and configured to increase the number of frictional surfacesbetween the pair of adjacent links. In some embodiments, there is arecessed portion on the surface of the each of links in the pair ofadjacent links sized and shaped to conform to the size and shape of aportion of a component in the brake assembly. The size and shape of therecessed portion will vary with the particular brake assembly designimplemented. By way of example, the recessed portion on the surface ofthe each of links in the pair of adjacent links has a generallyrectangular shape or, alternatively, a generally arcurate shape.

The brake assembly is spaced apart from the at least one hinge. In oneaspect, the brake assembly is spaced apart about 90 degrees about thecircumference of the link from the at least one hinge. Practicallimitations of the actual design of a specific instrument may alter thelocation of the braking mechanism. The spacing may be as close aspractical to 90 degrees from the hinge location.

In some embodiments, the brake assembly may also include a plurality ofcomplementary shaped components. The complementary shaped components mayhave surfaces adapted and configured to provide sliding motion whenlinks move about the hinge. The complementary shaped components may comein virtually any shape and orientation that allow sliding, relativemovement. In one example, the plurality of complementary shapedcomponents may be provided by a plurality of interwoven slats. This isone example where the complementary surfaces are generally flat. Instill another example, the complementary surfaces are generallyarcurate. In still another aspect, a complementary shaped componentpositioned adjacent one link in the pair of links moves along with themovement of the other of the links in the pair of links.

In one aspect of the present invention, vacuum applied to the instrumenttis used to lock or rigidize the elongate body. In other aspects of theinvention, a cable extending through or along the instrument is used toengage the brake assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe claims that follow. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which.

In the drawings:

FIG. 1 illustrates an exemplary controllable segmented instrument andassociated components of a control and interface system;

FIG. 2 is a view of a segment having a number of links joined by hinges;

FIGS. 3A, 3B and 3C illustrate the movement of an exemplary segmentthought the use of three actuation cables connected to the segment;

FIGS. 4A, 4B, 4C and 4D illustrate various views of a vertebra stylecontrol ring;

FIG. 5 illustrates a segment and its associated control cables ortendons and a drive motor used to drive one of the tendons to controlthe movement of the segment;

FIGS. 6, 7 and 8 illustrate various embodiments of a segmentedinstrument having an embodiment of a vacuum brake assembly;

FIGS. 9, 10, 11, and 12 illustrate various views of an embodiment of acontrollable instrument having braking capabilities;

FIGS. 13, 14, 15A, 15B and 16 illustrate various views of anotherembodiment of a controllable instrument having braking capabilities;

FIG. 17 illustrates an isometric view of another embodiment of acontrollable instrument having braking capabilities;

FIG. 18 illustrates an embodiment of an controllable instrumentpositioned within the esophagus and the stomach; and

FIG. 19 illustrates an embodiment of a controllable instrument having adistal section with articulatable and lockable segments in differentorientations.

DETAILED DESCRIPTION

FIG. 1 depicts a flexible endoscope 10, in accordance with an embodimentof the present invention. Endoscope 10 has elongate body 12 withsteerable distal portion 14, automatically controlled proximal portion16, and flexible and passively manipulated proximal portion 18. Theskilled artisan will appreciate that automatically controlled proximalportion 16 may also be flexible and passively manipulated, although itis preferred to provide automatically controlled proximal portion 16.The skilled artisan will also appreciate that elongate body 12 can haveonly steerable distal portion 14 and automatically controlled portion16. Fiber optic imaging bundle 20 and illumination fiber(s) 22 mayextend through elongate body 12 to steerable distal portion 14, or videocamera 24 (e.g., CCD or CMOS camera) may be positioned at the distal endof steerable distal portion 14, as known by the skilled artisan. As theskilled artisan appreciates, a user views live or delayed video feedfrom video camera 24 via a video cable (e.g., wire or optical fiber, notshown) or through wireless transmission of the video signal. Typically,as will be appreciated by the skilled artisan, endoscope 10 will alsoinclude one or more access lumens, working channels, light channels, airand water channels, vacuum channels, and a host of other well knowncomplements useful for both medical and industrial endoscopy. Thesechannels and other amenities are shown generically as 26. In particularthese amenities may include multiple tool channels in order to provideaccess for tools to a surgical site by passing the endoscope through anatural orifice proximate to a surgical target site, as in naturalorifice transluminal (or transgastric) endoscopic surgery (NOTES).

Preferably, automatically controlled proximal portion 16 comprises aplurality of segments 28, which are controlled via computer and/orelectronic controller 30. Such an automatically controlled endoscope isdescribed in further detail in commonly assigned U.S. patent applicationSer. No. 10/229,577 (now U.S. Pat. No. 6,858,005) and Ser. No.11/750,988, both previously incorporated herein by reference.Preferably, the distal end of a tendon (more thoroughly described below)is mechanically connected to a each segment 28 or steerable distalportion 14, with the proximal end of the tendon mechanically connectedto actuators to articulate segments 28 or steerable distal portion 14,which is more fully described below and in U.S. patent application Ser.No. 10/229,577 (now U.S. Pat. No. 6,858,005) and Ser. No. 11/750,988,both previously incorporated herein by reference. The actuators drivingthe tendons may include a variety of different types of mechanismscapable of applying a force to a tendon, e.g., electromechanical motors,pneumatic and hydraulic cylinders, pneumatic and hydraulic motors,solenoids, shape memory alloy wires, electronic rotary actuators orother devices or methods as known in the art. If shape memory alloywires are used, they are preferably configured into several wire bundlesattached at a proximal end of each of the tendons within the controller.Segment articulation may be accomplished by applying energy, e.g.,electrical current, electrical voltage, heat, etc., to each of thebundles to actuate a linear motion in the wire bundles which in turnactuate the tendon movement. The linear translation of the actuatorswithin the controller may be configured to move over a relatively shortdistance to accomplish effective articulation depending upon the desireddegree of segment movement and articulation. In addition, the skilledartisan will also appreciate that knobs attached to rack and piniongearing can be used to actuate the tendons attached to steerable distalportion 14. An axial motion transducer 32 (also called a depthreferencing device or datum) may be provided for measuring the axialmotion, i.e., the depth change, of elongate body 12 as it is advancedand withdrawn. As elongate body 12 of endoscope 10 slides through axialmotion transducer 32, it indicates the axial position of the elongatebody 12 with respect to a fixed point of reference. Axial motiontransducer 32 is more fully described in U.S. patent application Ser.Nos. 10/229,577 and 11/522,305, previously incorporated herein byreference. Additionally, an optical sensor may be used to determine theaxial position of the endoscope, either alone or in combination with anoptical shape sensor. In addition to the patents, patent applications,periodicals and other references cited below, NeoGuide Systems hasdesigned a fully segmented controllable instrument. An exemplaryinstrument is described in U.S. Pat. No. 6,858,005 entitled TendonDriven Endoscope. Additional details of a depth measurement system aredescribed in U.S. patent application Ser. Nos. 10/988,212 and10/384,252.

In the embodiment depicted in FIG. 1, handle 34 is connected toillumination source 36 by illumination cable 38 that is connected to orcontinuous with illumination fibers 22. Handle 34 is connected toelectronic controller 30 by way of controller cable 40. Steeringcontroller 42 (e.g., a joy stick) is connected to electronic controller30 by way of second cable 44 or directly to handle 34. Electroniccontroller 30 controls the movement of the segmented automaticallycontrolled proximal portion 16.

Referring to FIG. 2, steerable distal portion 14 and segments 28 ofautomatically controlled proximal portion 16 are preferably constructedfrom a plurality of links 46. Five links 46 are shown in this examplefor the sake of clarity, although the skilled artisan will recognizethat any number of links may be used including just one link, theultimate number being primarily defined by the purpose for whichsegments 28 or steerable distal portion 14 will be used. Each joint 47connects one link (e.g., 46) to an adjacent link (e.g., 46). Each link46, in this embodiment, can move with one degree of freedom relative toan adjacent link, and more than one link hinged together provides twodegrees of freedom.

Referring now to FIG. 3A-C a schematic diagram of either steerabledistal portion 14 or segments 28 is provided for discussion purposes andto explain a preferred system and method for articulating steerabledistal portion 14 or segments 28. The skilled artisan will recognizethat the system and method for articulation is the same for bothsteerable distal portion 14 and segments 28 of automatically controlledproximal portion 16. Therefore, the system and method for articulationwill be described referring only to segments 28, with the recognitionthat the description also applies equally to steerable distal portion14. It is noted that details relating to links 46, joints 47 and theinterconnections of the links have been eliminated from this figure forthe sake of clarity.

FIG. 3A shows a three-dimensional view of segment 28 in itssubstantially straight configuration. The most distal link 46A and mostproximal link 46B are depicted as circles. Bowden cables extend down thelength of elongate body 12 (not shown in FIG. 3A-C) and comprise coilpipes 48 and tendons 50. The proximal end of the Bowden-type cable iscoupled to an actuator (not shown) and the distal end is coupled to thesegment for which it controls articulation. Coil pipes 48 house tendons50 (i.e. a Bowden-type cable) along the length of elongate body 12 (notshown in FIG. 3A-C) and coil pipes 48 are fixed at the proximal end ofsegment 28. Tendons 50 extend out of coil pipes 48 at the proximal endof segment 28 along the length of segment 28, and are mechanicallyattached to the distal portion of segment 28. It will be appreciatedthat the distal end of tendons 50 need only be attached to the segment(or link if a segment is made up of only one link) being articulated bythat tendon 50 at a location required to transfer the actuated force tothat segment to effect articulation; the distal portion of the segmentis provided by way of explanation and example, and not by way oflimitation. In the variation depicted in FIG. 3A-C four tendons 50 aredepicted to articulate segment 28, but more or fewer may be used. Thecoil pipe/tendon combination, or Bowden cables, can be used to applyforce to articulate segments 28 and can be actuated remotely to deliverforces as desired to articulate segments 28. In this manner, actuationof one or more tendons 50 causes segment 28 to articulate. In theembodiment depicted, links 46 have joints 47 alternating by 90 degrees(see FIGS. 2 and 4). Thus, an assembly of multiple links 46 is able tomove in many directions, limited only by the number of actuated joints.As will be appreciated by the skilled artisan, tendons 50 can be madefrom a variety of materials, which is primarily dictated by the purposefor which the endoscope will be used. Without limitation tendons 50 canbe made from stainless steel, titantium, nitinol, ultra high molecularweight polyethylene, the latter of which is preferred, or any othersuitable material known to the skilled artisan.

In the variation depicted in FIG. 3A-C, four tendons 50 are used toarticulate segment 28, although more or fewer tendons could be used, aswill be appreciated by the skilled artisan. Four tendons can reliablyarticulate segment 28 in many directions. Tendons 50 are attached at themost distal link 46A, for the purposes of this discussion but not by wayof limitation, close to the edge spaced equally apart at 12, 3, 6, and 9O'clock. It will also be noted that an equal angle approximation hasbeen made with this figure, that is the amount of bend is equallydistributed to each of the joints of a segment.

FIG. 3B-C show segment 28 articulated by independently pulling orslacking each of the four tendons 50. For example, referring to FIG. 3B,pulling on tendon 50 at the 12 O'clock position and easing tension ontendon 50 at the 6 O'clock position causes steerable distal portion 28to articulate in the positive y-direction with respect to the z-y-xreference frame 52. It is noted that the most distal z-y-x coordinateframe 52 _(distal) rotates with respect to the z-y-x reference frame 52and that β is the degree of overall articulation of segment 28. In thissituation 13 is only along the positive y-axis, up, because only tendon50 at the 12 O'clock position was pulled while easing tension or givingslack to tendon 50 at 6 O'clock. The tendons 50 at 3- and 9 O'clock wereleft substantially static in this example, and, thus, had approximatelyno or little affect on articulation of segment 28. The reverse situation(not depicted), pulling on tendon 50 at the 6 O'clock position andslacking or easing the tension on tendon 50 at the 12 O'clock positionresults in articulation of segment 28 in the negative y-direction, ordown. Referring to FIG. 3C the same logic applies to articulate segment28 in the positive x-direction (right) or a negative x-direction (left,not shown). Segment 28 can be articulated in any direction by applyingvarying tensions to the tendons off axis, e.g., applying tension to thetendons at 12 O'clock and 3 O'clock results in an articulation up and tothe left.

Referring now to FIG. 4, links 46 may be control rings to provide thestructure needed to construct steerable distal portion 14 and segments28. Vertebrae-type control rings 54 have two pairs of joints or hinges58A and 58B; the first pair 58A projecting perpendicularly from a firstface of the vertebra and a second pair 58B, located 90 degrees aroundthe circumference from the first pair, projecting perpendicularly awayfrom the face of the vertebra on a second face of the vertebra oppositeto the first face. Hinges 58A and 58B are tab-shaped, however othershapes may also be used.

FIG. 4C-D shows vertebra-type control ring 54 in sectional andperspective views. Control ring 54 comprises body 66, which is hingedlycoupled to inner cross bar member 57 at joints 59. Joints 59 are thesame joints at which a second link (although not shown) adjacent andproximal to link 54 is hingedly coupled to link 54. Inner cross barmember 57 is therefore hingedly coupled to two links at joints 59, andcan be thought of as being axially disposed “between” the two links.Cross bar member 57 can also be fixed relative to one or both of theadjacent links. The exemplary inner cross bar member 57 comprises forcemodifying elements 104 or purchase which each interact with a tendon 50(not shown in FIGS. 4D and 4E) to increase the amount of force appliedto the articulatable segment when an actuation/tensioning force isapplied to the tendon. Bar 105 is provided as a tie-anchor for a tendoncoming back down the segment from the purchase.

The skilled artisan will appreciate that coil pipes 48 by-passing avertebrae via quadrants 68 will define an approximately cylindrical coilpipe containment space roughly defined by the outer diameter ofvertebrae-type control ring 64. Management of the coil pipes is morethoroughly discussed in co-assigned U.S. patent application Ser. No.11/871,104 previously incorporated herein by reference. This space isloosely defined by the grouped coil pipes as they pass through andbetween the vertebrae. As described more thoroughly below, it ispossible and preferred to have intermediate vertebra-type control ringswithout coil pipe bypassing spaces and therefore without cross-bars 57.In either construction, central aperture 56 or 56′ of the control ringscollectively forms a lumen (not shown) through which channels and cablesnecessary or desired for the endoscope function pass, as well as coilpipes and tendons by-passing that particular segment.

Referring to FIG. 5, coil pipes 48 are fixed at their distal andproximal ends between actuators 60 and the proximal end of segment 28under control by those actuators. FIG. 5 shows only one segment 28(which, as discussed, could also be steerable distal portion 14), and,for clarity, the other parts of a complete endoscope have been omittedfrom FIG. 5. When tendons 50 are placed under tension, the force istransferred across the length of segment 28; coil pipes 48 provide theopposite force at the proximal end of the segment being articulated inorder to cause the articulation. This force is, primarily, axial loadingtransferred along the length of the coil pipe where it is fixed betweenthe actuator and the proximal end of the segment being articulated. Apreferred embodiment of the present invention utilizes one actuator pertendon, and utilizes four tendons per segment, as described above,although only one actuator 60 is depicted for clarity. Details relatingto actuator 60 and connecting actuator 60 to tendons 50 are described inU.S. patent application Ser. No. 10/988,212, previously incorporated byreference.

The skilled artisan will appreciate that articulation of multiplesegments 28 along the length of elongate body 12 will require that manycoil pipes 50 extend down the length of elongate body 12 and throughcoil pipe by-passing spaces, with the number decreasing by four coilpipes (in this example) at the proximal end of each segment. Thus, a 17segmented elongate body (16 segments 28 and 1 tip 14) requires 68 coilpipes going into the proximal end of elongate body 12, which decreasesby four coil pipes for each distally adjacent segment 28 (assuming oneuses four tendon/coil pipes combinations per segment as in the presentexample). It also requires the actuation or tensioning of 68 tendons,with four tendons terminating at the distal end of each segment. Thisrequires 68 actuators in this embodiment, one actuator per tendon 50.

The skilled artisan will also appreciate that there is not a one to onecorrespondence between the force applied by actuators 60 at the proximalend of tendons 50 and the force realized at the distal end of tendons 50to articulate segment 28. Friction between tendons 50 and coil pipes 48results in frictional losses along the length of the coil pipe whileapplying tension to articulate a segment or the tip. Articulation ofsegments 28 and steerable distal portion 14 results in further lossesand inefficiencies for many reasons. For example, and withoutlimitation, when elongate body 12 articulates (for example at theSigmoid colon during a colonoscopy procedure or when retroflexing ornavigating upon exiting the stomach in a NOTES procedure), coil pipes 48must move longitudinally along elongate body 12 to either “gain” or“lose” length depending whether coil pipes 48 are on the inner or outerportion of the bend created by the articulation. As described above, anembodiment of the present invention provides quadrants 68 or coil pipeby-passing spaces 62 that permit the passage of coil pipes 48 alongelongate body 12 until they reach the proximal portion of the segmentthey control. The “gain” or “loss” of coil pipe length requires coilpipes 48 to slide up and down elongate body 12 and within quadrants 68or coil pipe by-passing spaces 62 creating further frictional losses byvirtue of friction between the coil pipes and/or between the coil pipesand the vertebra. There is also the additional friction created betweena coil pipe and a tendon by virtue of the bend. Additionally, butrelated, elongate body 12 may enter more than one tortuous bendsimultaneously. This may occur when going through a tortuous path suchas the colon or when navigating the scope in open space (e.g., withinthe peritoneal cavity) to perform NOTES procedures. In one mode ofoperation, as described more thoroughly in U.S. patent application Ser.No. 11/019,963, previously incorporated herein by reference, electronicmotion controller 30 causes adjacent segments to adopt the shape of thesegment or steerable distal portion immediately preceding it. Asdescribed above, coil pipes 48 need to slide along elongate body 12 toaccommodate the “gain” or “loss” of coil pipe length resulting from thearticulation of elongate body 12. In order to localize this “gain” or“loss” the coil pipes are spiraled. In effect, it is believed, spiralinglocalizing the sliding of the coil pipes to the segment, therebypreventing binding of the coil pipes and catastrophic failure. This isdescribed in further detail in co-pending, co-assigned U.S. patentapplication Ser. No. 11/871,104 titled System for Managing Bowden Cablesin Articulating Instruments.

Performing procedures within a patient, such as in natural orificetransluminal endoscopic surgical procedures, may require a stable,semi-rigid platform from which to perform the procedure. Lockable tubesin the prior art have the surface of one ring contacting the surface ofan adjacent ring. Compression of the adjacent rings in these prior artlockable tubes increases the friction between the adjacent rings causingthem to resist articulation relative to each other.

In contrast to conventional locking approaches, embodiments of theinventions described herein provide additional frictional surfaces or insome embodiments multiplied frictional surfaces between articulatingcomponents. It is believed that the additional surfaces increase thefrictional surface acting on the instrument. The additional frictionalforce in turn increases the braking or locking force applied to theinstrument. Various embodiments of the present invention providemechanisms by which the user can selectively rigidize all or a portionof the elongate body through the use of multiple surfaces placed betweenarticulating segments or individual links or vertebra. In addition,while the braking assemblies described herein provide multipliedfriction and lock force, they remain capable of articulation when notengaged. In some embodiments, the brake assembly includes the hinge orportion of a hinge or joint used for the articulation of the segmentedinstrument.

In one aspect, there is provided a segmented instrument having aplurality of links and at least one lockable and articulatable jointpositioned to connect a pair of adjacent links in the plurality oflinks. In addition, the at least one lockable and articulatable jointbeing adapted and configured to increase the number of frictionalsurfaces available between the pair of adjacent links. As describedabove, cables and coil pipes take up a large amount of space along theelongate body. In one aspect, the brake assembly lies on or in theexterior surface of the segment, hinge or vertebra in order to keep theinterior portions of the instrument free.

In one embodiment of the present invention, there is a segmentedinstrument having braking capabilities. The instrument includes anelongate body having a plurality of links. The instrument may beconfigured as any of a wide variety of surgical devices. For example,the instrument may be an endoscope or other controllable instrument asdescribed above or it may be a guide used to direct the movement orplacement of another instrument including another segmented instrument.A hinge connects a pair of adjacent links in the plurality of links.There is a brake assembly coupled to each link in the pair of adjacentlinks. The brake assembly is positioned to span the distance between thepair of adjacent links.

The skilled artisan will readily recognize appropriate materials fromwhich to make components in a brake assembly. The desired properties ofthe materials used in a brake assembly include lubricity between layerswhen the brake is not actuated (e.g., braking force is not applied or novacuum is pulled) and sufficient friction to bind the components orbrake assembly when the brake is actuated (e.g., the braking force isapplied or a vacuum is pulled). Another useful property is that thebrake assembly has the flexibility to bend when a joint is articulated.Exemplary materials for use in brake assembly components include,without limitation, aluminum, carbon fiber, and various plastics such asand without limitation Teflon®.

The brake assembly may be on all or only some of the links, vertebra orsegments of an instrument. The brake assembly or multiple brakeassemblies may be placed in isolated or only specific portions of theinstrument. Numerous actuation mechanisms may be used to engage thebrake assembly or assemblies. In one aspect, the brake assemblies areactivated by pulling a cable running through or along the instrument. Inanother alternative form of activation, the interior of the scope (anormally sealed environment) is pumped down so that the interior isunder vacuum. The action of the skin of the instrument being pulled inby the vacuum may be used to actuate a braking mechanism. In addition,the brake assemblies may be activated serially or simultaneously or inany order depending upon circumstances in use. The brake assembly orassemblies may be provided only in a distal portion of the links in theplurality of links. Alternatively, the brake assembly is provided onlyin a proximal portion of the links in the plurality of links. In stillanother alternative, the brake assembly is provided only in a middleportion of the links in the plurality of links.

The movement of the pair of adjacent links about the hinge is preventedwhen the brake assembly is engaged. In one aspect, the brake assembly isprovided only between a portion of the links in the plurality of links.There are configurations of the braking assembly where one or more areplaced wherein the actuation of the brake assembly removes one degree offreedom from a portion of the instrument. In other aspects, a pluralityof brake assemblies are coupled to the instrument. In this example, theactuation of the plurality of brake assemblies substantially locks theshape of instrument by locking substantially all of the plurality oflinks in the instrument. In an alternative configuration, the pluralityof brake assemblies are coupled to the instrument wherein actuation ofthe plurality of brake assemblies substantially removes one degree offreedom from the movement of the segmented instrument.

In addition, the brake assembly is adapted and configured to complementthe operation of the hinge so that the hinge remains articulatable whenthe brake assembly is not actuated or engaged. The brake assembly isadapted and configured to increase the number of frictional surfacesbetween the pair of adjacent links. In some embodiments, there is arecessed portion on the surface of the each of links in the pair ofadjacent links sized and shaped to conform to the size and shape of aportion of a component in the brake assembly. The size and shape of therecessed portion will vary with the particular brake assembly designimplemented. By way of example, the recessed portion on the surface ofthe each of links in the pair of adjacent links has a generallyrectangular shape or, alternatively, a generally arcuate shape.

The brake assembly is spaced apart from the at least one hinge. In oneaspect, the brake assembly is spaced apart about 90 degrees about thecircumference of the link from the at least one hinge. Practicallimitations of the actual design of a specific instrument may alter thelocation of the braking mechanism. The spacing may be as close aspractical to 90 degrees from the hinge location.

In some embodiments, the brake assembly may also include a plurality ofcomplementary shaped components. The complementary shaped components mayhave surfaces adapted and configured to provide sliding motion whenlinks move about the hinge. The complementary shaped components may comein virtually any shape and orientation that allow sliding, relativemovement. In one example, the plurality of complementary shapedcomponents may be provided by a plurality of interwoven slats. This isone example where the complementary surfaces are generally flat. Instill another example, the complementary surfaces are generallyarcurate. In still another aspect, a complementary shaped componentpositioned adjacent one link in the pair of links moves along with themovement of the other of the links in the pair of links.

One embodiment of the present invention uses a vacuum mechanism to lockor rigidize the elongate body. FIGS. 6, 7 and 8 will now be used toexplain the operation of one embodiment of an instrument having brakingor locking capabilities. FIG. 6 is an isometric view of an instrumentwith an embodiment of a brake assembly 700. FIG. 7 is an enlargedsection view of a brake assembly 700 in FIG. 6. FIG. 8 illustrates asection view of two links and the forces applied to the brake assemblyby the instrument skin 600.

As best seen in FIGS. 7 and 8 the instrument elongate body 12 has skin600 over its outside. Skin 600 is preferably made from some smooth,elastic and durable material in order to prevent trauma to the patientas elongate body 12 is moved about within the patient.

FIG. 6 is an isometric view of a portion of an instrument having sixlinks 46. This view shows the instrument without skin 600 so that theposition of the brake assembly 700 may be seen in relation to the hinge47. In this embodiment, a brake assembly 700 is attached betweenadjacent links 46. In the illustrative embodiment of FIG. 6, the brakeassembly 700 is located approximately ninety degrees about thecircumference of link 46 from joint 47. The brake assemblies 700, whenengaged, substantially prevent articulation of link 46 about its joint47. Thus, when a brake assembly 700 is engaged the degree of freedomprovided in each link is substantially removed. When a plurality ofbrake assemblies acts together, they substantially rigidize or lock theelongate body 12 in the shape existing when the brake assembly isactuated.

FIG. 7 illustrates a partial section view of an embodiment of a brakeassembly 700 shown in FIG. 6. Referring to FIG. 7, brake assembly 700,in one embodiment, includes interwoven slats or layers 800. Interwovenslats or layers 800 slide next to and between each other and are securedon either side of hinged links 46 by pins 802. Slats or layers 800A areattached to link 46A using pin 802A. Slats or layers 800B are attachedto link 46B using pin 802B. The location of pins 802A, B and the lengthof the slats or layers 800A, 800B are selected so that the overlappingregion 800C exists throughout the range of motion for the hinge 47 (notshown) associated with links 46A, 46B. By selecting the proper length ofslats 800A, 800B with a sufficient overlapping region 800C, the brakeassembly 700 can engage irrespective of the relative position of links46A, 46B. This sliding arrangement of the slats/layers 800A, 800B whichpermits articulation of joint 47 when brake assembly 700 is not engaged.

In this embodiment, a vacuum is pulled within elongate body 12, and thepressure difference causes skin 600 to apply a force against links 46and against brake assembly 700, as depicted by arrows in FIG. 8. Thisforce acts against the brake assembly 700 causing the interwoven slatsor layers 800A, 800B to engage by pressing layers 800A, 800B together inthe overlapping region 800C as well as against each other and thesurface of the links 46A, 46B. The increase of friction between layers800A, 800B upon application of the force causes brake assembly 700 toengage, thereby inhibiting articulation of the joint across which thebrake assembly spans. Release of the vacuum removes the force applied tobrake assembly 700 by the skin 600, thereby permitting sliding movementagain between the slats 800A, 800B and articulation of the joints andthe elongate body.

Also shown in FIG. 8 is the recessed portion 809. The recessed portion809 is positioned on the surface of the each of links 47 in the pair ofadjacent links. The recessed portion 809 is sized and shaped to conformto the size and shape of a portion of a component in the brake assembly.In this illustrative example, the size and shape of the recessed portion809 corresponds to the size of the slats 800A, 800B and is generallyrectangular like the slats 800A, 800B. The size and shape of the recess809 will vary with the specific brake assembly or technique beingutilized. In an alternative embodiment, the recessed portion on thesurface of the each of links in the pair of adjacent links may have agenerally arcurate shape, a curved shape, an irregular shape or acompound shape.

In alternative embodiments of the present invention, one or more cables(preferably different from the actuation tendons) running along orthrough the edges of links 46 of elongate body 12. Each joint of eachvertebrae or link 46 has brake assembly or articulating lockable brakeassembly as described herein. In one aspect, the various alternativebrake assemblies have multiple surfaces that slide next to each otherabout a pivot point when force is not applied, thereby permittingarticulation of the link. One aspect of the embodiments of the brakeassemblies described herein that allows the surfaces to effectivelymultiply the friction at the joint is that the sliding plates betweenthe rings can move freely separate along the central axis of the rings,but cannot rotate relative to either the upper or lower ring dependingon which one they are contiguous with. In other words, when load isremoved from the joints, the components are allowed to separate,facilitating articulation. When load is applied to the joints, thesurfaces compress and friction is generated at the interfaces, resistingarticulation. This design is not limited to just three interfaces asdepicted in some embodiments described herein. For a given load, byincreasing the number of frictional interfaces increases the resistanceto articulation.

The multiple surfaces of the brake assemblies bind when load is placedon the links, in this embodiment by applying tension to the cables. Theapplied tension compresses the links together, which in turn compressesmultiple surfaces together preventing the links from articulating, and,thereby, rigidizing elongate body 12. This design is not limited to justthe number of interfaces depicted. For a given load, increasing thenumber of frictional interfaces increases the resistance toarticulation.

In some aspects, one or more brake assembly components may be part ofand contiguous with a link structure. In other configurations, one ormore brake assembly components may be slidingly pinned into a linkstructure such that it can have limited movement longitudinally up anddown relative to a link structure. In this regard, it may in essence bepart of a link structure as well. Other brake assembly components may beattached to a link structure 46 by pivot arms and such that thesesurfaces may articulate along upper arched surfaces or othercomplementary surfaces of 958 of a link structure 46. In someembodiments, one can see each link structure 46 contributes two surfacesto either side of a brake assembly, for a total of three contactsurfaces for each joint. In addition and where needed, holes areprovided in link structure 46 for the passage of cables 900 used toarticulate the links and other cables to compress the multiple surfacestogether, thereby locking link structures relative to each other. Whennot compressed, the surfaces described above and in the various brakeassembly embodiments will slide relative to each other to permit bendingor articulation of the controllable instrument (e.g. guide tube orsegmented controllable instrument) made from the ring structures andbrake assemblies.

The components of the brake assembly 900 are compressed via a cable thatruns through links 46, as previously described. Tension in the cables isgenerated using a lead screw with a balance bar to distribute the loadevenly between joints. Any method that generates a compressive load isacceptable given that the loads do not act to articulate the joint, butrather to compress it. The compressive load should act directly throughthe pivot point of the joint if possible.

It is further noted that articulation of each link has one degree offreedom, as described above. Preferably, the direction of the degree offreedom alternates for adjacent links and is orthogonal for adjacentlinks. In this manner segments made of multiple links can be articulatedin multiple directions using tendons and actuators, as described above.In this embodiment the articulating elongate body can be selectivelyrigidized by actuating the cables. In an alternative embodiment, themultiplying surfaces can be used to selectively rigidize an over tube,which is used to guide an instrument. The instrument can either be apassive endoscope, such as that made by Olympus, or a fully controlledarticulating scope, such as that described above and in development byNeoGuide Systems, Inc.

Turning now to FIGS. 9-12 that illustrate various views of anotherembodiment of a segmented instrument having braking capabilities. Asshown in FIG. 9, there is an illustration of an elongate body having aplurality of links 46. There is a hinge connecting a pair of adjacentlinks in the plurality of links and a brake assembly 900 coupled to eachlink in the pair of adjacent links. The brake assembly 900 is alsopositioned to span the distance between the pair of adjacent links 46. Acable 92 extends through the plurality of brake assemblies 900 to astopper 93 on the distal end. When the cable 92 is drawn proximallyeither manually by a user or by a motor or other drive system under thecontrol of a computer controller, the stopper 93 engages with thecomponents of the brake assembly 900 to engage and lock the position ofthe segmented instrument.

The internal components of the brake assembly 900 are best seen in theviews provided by FIGS. 10, 11 and 12. FIGS. 10 and 11 provide side andisometric views, respectively, of at least two links coupled together bythe brake assembly 900. The specific components of the brake assemblywill now be described with reference to the exploded view of FIG. 12.

FIG. 12 illustrates an exploded view of the components of an exemplarybrake assembly 900. The link 46 includes a brake assembly base 905having shaped upper complementary surface 910 and lower shapedcomplementary surface 915. Apertures 918U, 918L are formed in the baseare sized and positioned to receive the common pins 925 provided by arms920. Apertures 955 are sized and positioned to receive pins 950 of thelink slider 940. Arm 920 includes common pins 925T on one end and pins925B on the other. The pins 925T couple to apertures 918L and the pins925B couple to the apertures 918U. The common pins and the arms providethe hinge between the links and allow for relative movement betweenadjacent links. The arms 920 shown in the view of FIG. 12 illustrate theconnection between pins 918U into aperture 918U of the link 46 shown inthe figure.

The arm 920 also passes through the arm slider 930 and link slider 940.Arm slider 930 includes an aperture 935 for the arm 920. Link slider 940includes an aperture 945 for the arm 935. The arm slider 930 is shapedto provide complementary surfaces for both the base upper surface 910 toone side and the base lower surface 915 to the other. As shown in theviews of FIGS. 10 and 11, when the brake assembly 900 is in use, the armslider 930 is in sliding relation and has complementary shape to slidebetween the link upper and lower surfaces 910, 915. The arm slider movesindependent of the links 46 and provides additional friction surfaces tolock the relative position of the links 46. The link slider 940 alsoprovides additional friction lock surfaces. In contrast to the armslider 930, the link slider 940 is pinned to the link using the pins 950and apertures 955. As such the link slider moves with the link 46. Thelink slider 940 has complementary shaped surfaces that provide theincreased number of friction surfaces between the base lower surface 915and the arm slider 930 and the base upper surface 910.

As best seen in the assembled views of FIGS. 10 and 11, both the armslider 930 and the link slider 940 have apertures adapted and configuredto fit around and permit passage of the arm 920. In this embodiment ofthe brake assembly 900, the complementary surfaces and increasedfriction lock surfaces are, from the base lower surface 915 of the upperlink 46: lower base surface 915 contacts the upper surface of the armslider 930, the lower surface of the arm slider 930 contacts the uppersurface of the link slider 940 and the lower surface of the link slider940 contacts the upper base surface 910 of the lower link 46. Each ofthe above surfaces has a complementary shape that allows slidingmovement and articulation of the links 46 when the brake 900 is notengaged. When engaged, the surfaces and components above act in concertto lock the relative position of the links 46.

FIGS. 13-16 illustrate another alternative embodiment of a segmentedinstrument having braking capabilities. The brake assembly 1400 is shownin use on an elongate body having a plurality of links 46. There is ahinge provided within the brake this embodiment of the brake assembly1400 that connects a pair of adjacent links 46 as shown in FIGS. 13, 14and 15B. The brake assembly 1400 is coupled to each link 46 in the pairof adjacent links and positioned to span the distance between the pairof adjacent links. Similar to the brake assembly 900, the brake assembly1400 also includes components that have complementary shapes, providefor relative movement when the brake is not engage and multiply thenumber of friction surfaces when the brake 1400 is engaged. Theindividual components of the brake assembly 1400 are best seen in theviews of FIGS. 15A and 16. The brake assembly 1400 includes a carrierplate 1410, a central sliding block 1405 and arms 1425 having armsliders 1430. A lock plate 1440 (shown in FIGS. 14 and 14) is used tosecure components to the carrier plate 1410. Returning to FIGS. 15A and16, the arms 1425 include apertures 1435 for the common pivot pin 1420,best seen in FIG. 15A. Continuing to refer to FIG. 15A, pulling thecable 92 will decrease the spacing between central block 1405, armsliders 1430 and base sliders 1415 and bring the complementary surfacesof these components into locking contact. Similar to the brake assembly900, the added friction surfaces will act to enhance the lockingcapabilities provided by the brake assembly 1400. Both sides of the armslider are engaged as it is compressed between the central sliding block1405 and the base slider 1415.

FIGS. 14 and 15 provide additional views of a plurality of links 46joined together by a number of brake assemblies 1400. FIG. 14illustrates the cables 92A, 92B that may be used independently or inconcert to actuate the brake assemblies 1400. FIG. 13 illustrates acentral lumen 1470 in relation to the links 46. The central lumen 1470could be another instrument, as would be the case when the plurality oflinks 46 shown is configured to act as a guide tube. Alternatively, thecentral lumen 1470 could be the interior components of a instrument(working channels, provisions for light, air, water and videocapabilities commonly provided in endoscopy for example) when theplurality of links are configured as part of a controllable segmentedinstrument. In addition, control cables and other components describedabove and else where in this application would also be provided in orderto provide steering control of the instrument formed by the links 46.

FIG. 17 illustrates still another alternative embodiment of a brakeassembly according to the present invention. FIG. 17 is an isometricview of a segmented instrument having braking capabilities provided bythe brake assembly 1800. As shown, there is an elongate body having aplurality of links 46A, 46B and 46C. There is a hinge connecting a pairof adjacent links in the plurality of links provided by the brakeassembly 1800. In addition, the brake assembly 1800 is coupled to eachlink in the pair of adjacent links and positioned to span the distancebetween the pair of adjacent links. In the illustrative embodiment, abrake assembly 1800 spans the distance between the link 46A and 46B andanother brake assembly spans the distance between the links 46B and 46C.Similar to the previously described brake assemblies, the brake assembly1800 provides articulation and locking capabilities between adjacentlinks. Moreover, the configuration and interoperability of thecomponents of the brake assembly 1800 like the previous embodiments alsoprovides an increased number of friction locking surfaces to enhance andmagnify the applied locking force.

In the embodiment shown in FIG. 17, the brake assembly 1800 includes acentral sliding block 1805. A base slider plate 1810 is attached to thecentral sliding block 1805. A center plate 1815 is also attached to thecentral sliding block 1805 and is positioned between the base sliderplate 1810 and the hinge plate 1820 attached to the link 46B. Thecomplementary surfaces of the central sliding block 1805, base slider1810, center plate 1815 and the hinge plate 1820 allow for relative andsliding movement between these components, and the adjacent links 46when the brake assembly 1800 is not engaged. When the brake assembly1800 is engaged by pulling on the cable 92, the center plate is engagedbetween the base slider 1810 and the hinge plate 1820. In addition, thehinge plate 1820 is engaged to the complimentary surface 1825 of thelink. The base slider is engaged against the complementary surface ofthe central sliding block 1805.

It is to be appreciated that the various braking assemblies describedherein may be adapted and configured to operate in a number of differentcontexts. For example, the links and the brake assemblies may beconfigured to operate as an endoscope or other segmented controllableinstrument. Additionally, the links and braking assemblies may beconfigured to function as a guide tube so that another instrument maypass through the central lumen of the links 46. In still otheralternatives, the links and brake assemblies are configured into hybridinstruments having both highly controllable sections and the flexibleand lockable sections. In one exemplary embodiment, there is one sectionof the instrument that is segmented and configured to be highlyarticulating with many degrees of freedom and optimum flexibility andcontrollability. Examples of such instruments are those instrumentsdescribed above with regard to FIGS. 1-5. The proximal portion of thatcontrollable instrument may be configured to be flexible and includelocking assemblies. In this way, the hybrid instrument has articulationand control need in the surgical site while providing a proximal endthat may be used as a base or support for the distal end.

FIG. 18 is one exemplary embodiment of an instrument 1800 having adistal end 1810 and a proximal end 1805. The distal end includes hinges1815 and flexible segments 1820. The proximal end 1805 includes flexiblesegments 1830 and articulating brake assemblies 1825. The proximal endsegments 1830 are larger than the segments 1820 because the distal endin this embodiment is configured for greater articulation and controlcapabilities. In addition, the change in the size of the segments andcontrol of the instrument or function of the instrument changes at theflexible-base transition 1840. As shown in the illustrative embodimentof FIG. 18, the instrument 1800 is positioned in the alimentary canalwith the distal end positioned just prior to forming an opening in thestomach 1890 in furtherance of a transgastric or transluminal or otherNOTES procedure. Once the opening is formed and the distal end isadvanced, the distal end of highly articulating end could be advancedthrough the opening up to or beyond the transition point 1840. While theproximal end may be advanced through the transluminal opening, there areconfigurations where the relative lengths of the proximal and distalends are selected so that when the distal section is in the surgicalsite the proximal end in positioned and locked within the esophagus 1885and stomach 1890 to provide a base for the operation of the articulatingdistal end 1810. In still other embodiments, the hinges 1815 may also beconfigured as brake assemblies as described herein so that the distalend may articulate, including computer controlled articulation asdescribed herein, and also have the enhanced locking capabilities of thebrake assemblies of the present invention.

FIG. 19 is another exemplary embodiment of an instrument 1900 having adistal end 1905 and a proximal end 1823. The distal end 1905 includeshinges 1913 and flexible segments. The distal end 1905 is divided into adistal section 1910 where the hinges 1913 are aligned to providearticulation in a first orientation and a proximal section 1920 wherethe hinges 1913 are aligned to provide articulation in a secondorientation. The transition section 1915 is adapted and configured toprovide the transition between the different orientations of thearticulation in the distal section 1910 and the proximal section 1920.Similar to the embodiment in FIG. 18, the instrument 1900 also includesa proximal end 1923 that includes flexible segments 1830 andarticulating brake assemblies 1825. As before, the proximal end segments1830 are larger than the segments 1820 because the distal end in thisembodiment is configured for greater articulation and controlcapabilities. In addition, the change in the size of the segments andcontrol of the instrument or function of the instrument changes at theflexible-base transition 1840. As with the embodiment of FIG. 18 and theother embodiments, the embodiment of instrument 1900 may be placed inthe alimentary canal with the distal end positioned just prior toforming an opening in the stomach in furtherance of a transgastric ortransluminal or other NOTES procedure. Once the opening is formed andthe distal end is advanced, the distal end 1905 may be advanced throughthe opening up to or beyond the transition point 1840. While theproximal end 1923 may be advanced through the transluminal opening,there are configurations where the relative lengths of the proximal anddistal ends are selected so that when the distal section is in thesurgical site the proximal end in positioned and locked within theesophagus 1885 and stomach 1890 to provide a base for the operation ofthe articulating distal end 1905. In still other embodiments, the hinges1913, 1825 may also be configured as brake assemblies as describedherein so that the distal end may articulate, including computercontrolled articulation as described herein, and also have the enhancedlocking capabilities of the brake assemblies of the present invention.It is to be appreciated that the orientations between the distalsections 1910, 1920 may be changed or specifically adapted for aparticular procedure or NOTES access site.

While reference has been made to the use of the instruments describedherein in either their articulating or lockable forms as accessing asurgical site via the stomach, the uses of the invention are not solimited. Embodiments of the present invention may be modified andadapted as needed to facilitate entry and access to surgical site vianatural orifice (such as, for example, through the mouth, the anus/colonor the vagina or other openings formed once the instrument has accessedthe alimentary canal), surgically created openings includinglaparoscopic or single port access openings or other percutaneousopenings. In addition, other embodiments of the instruments havingbraking capabilities as described herein may be configured asrigidizable external working channels as well as rigidizable externalworking channels that can be separated from another scope or instrument.

In another aspect of the invention, the segmented instrument withbraking capabilities may also be used to aid a physician in theperformance of a surgical procedure. This aspect includes a method ofcontrolling a segmented instrument. First, there is a step ofintroducing a segmented instrument into a patient, the segmentedinstrument having a plurality of links wherein adjacent links are joinedby a hinge. Next, there is a step of manipulating the links about thehinges to maneuver the segmented instrument to provide access to asurgical site within the patient. In one aspect, the manipulating stepproduces a sliding motion between a plurality of complementary shapedcomponents within a portion of a brake assembly between adjacent links.Next, there is also a step of actuating the brake assembly tosubstantially prevent movement about the hinge of the links attached tothe braking mechanism.

As will be appreciated from the discussion above, the actuating step inthe method of controlling a segmented instrument may take any of severalforms. For example, the actuating step may include applying vacuum tothe interior of the segmented instrument. Alternatively, the actuatingstep comprises pulling a cable. It is to be appreciated that theactuating step substantially locks the shape of a portion of thecontrollable instrument.

Depending upon specific circumstances where the segmented instrument isbeing used, the method of controlling a segmented instrument may alsoinclude advancing a surgical implement through a working channel in thesegmented instrument to the surgical site. Additionally oralternatively, the advancing step is performed after the actuating step.In still other alternative methods, there is also a step of accessingthe surgical site with a controllable surgical instrument advancedthrough the segmented instrument. In addition, the advancing step isperformed before, after or during the actuating step.

It is to be appreciated that the inventive brake assemblies describedherein may be applied to the guide tubes and controllable segmentedinstruments and used in the various methods described in the co-pendingand commonly assigned application “METHODS AND APPARATUS FOR PERFORMINGTRANSLUMINAL AND OTHER PROCEDURES” filed on Sep. 14, 2006 as applicationSer. No. 11/522,305, now published patent application number US2007-0135803 (published on Jun. 14, 2007). In addition, the brakeassemblies and other details described herein may also be configured andcontrolled as those instruments in and used to perform the surgicalprocedures described in the commonly assigned and co-pending “APPARATUSAND METHODS FOR AUTOMATICALLY CONTROLLING AN ENDOSCOPE” filed on Jan.29, 2009 as PCT/US2009/032481.

1. (canceled)
 2. A segmented instrument, comprising: a body having afirst link, a second link, and a longitudinal axis, each of the firstlink and the second link being pivotably coupled together and configuredto articulate relative to one another about an axis of articulation; aplurality of slats extending in a longitudinal direction between thefirst and second links, the slats being disposed in layers formed in adirection perpendicular to the longitudinal axis; wherein, in a firststate, the plurality of slats are slideable relative to each other andthereby permit articulation of the first and second links relative toeach other; and wherein, in a second state, the plurality of slats arepressed against each other to inhibit sliding relative to each other andthereby inhibit articulation of the first and second links relative toeach other.
 3. The segmented instrument of claim 2, further comprisingan exterior covering surrounding the body at a location of the pluralityof slats.
 4. The segmented instrument of claim 3, wherein the exteriorcovering comprises an elastic material.
 5. The segmented instrument ofclaim 3, wherein the exterior covering is configured to apply a forceagainst the plurality of slats in a direction perpendicular to the axisof articulation in response to a vacuum applied interior to the exteriorcovering.
 6. The segmented instrument of claim 5, wherein the pluralityof slats is configured to be pressed against each other by the forceapplied by the exterior covering in response to the vacuum being appliedto the interior of the exterior covering.
 7. The segmented instrument ofclaim 2, wherein at least a portion of a shape of the segmentedinstrument is locked by the plurality of slats being pressed againsteach other in the second state.
 8. The segmented instrument of claim 2,wherein the segmented instrument is an endoscope.
 9. The segmentedinstrument of claim 2, wherein the segmented instrument is a guide tube.10. The segmented instrument of claim 2, wherein the plurality of slatscomprises a first slat connected at a first slat end portion to thefirst link and second slat connected at a second slat end portion to thesecond link, and wherein respective end portions of the first and secondslats opposite to the connected first and second slat end portions atleast partially overlap each other.
 11. The segmented instrument ofclaim 10, wherein the at least partially overlapping end portions of thefirst and second slats are configured to at least partially overlapthroughout a range of motion of the first and second links duringarticulation relative to each other.
 12. The segmented instrument ofclaim 11, wherein a frictional force between a surface of the first slatand a surface of the second slat at the at least partially overlappingend portions inhibits movement between the first link and the secondlink about the axis of articulation in the second state of the pluralityof slats.
 13. The segmented instrument of claim 2, wherein the pluralityof slats are disposed 90 degrees offset around the first and secondlinks from a location at which the first and second links are pivotablycoupled together.
 14. The segmented instrument of claim 2, whereinrecesses on a surface of the first and second links receive the endportions of the plurality of slats.
 15. The segmented instrument ofclaim 2, wherein the plurality of slats comprises a first plurality ofslats extending in a longitudinal direction between the first and secondlinks at a first angular location around the segmented instrument and asecond plurality of slats extending in a longitudinal direction betweenthe first and second links at a second angular location around thesegmented instrument, the second angular location being 180 degrees fromthe first angular location.
 16. The segmented instrument of claim 15,wherein the first angular location and the second angular location areoffset 90 degrees from the axis of articulation.
 17. A method ofcontrolling movement of a segmented instrument having a body comprisinga first link and a second link, the first link and the second link beingpivotably coupled along an axis of articulation, the method comprising:manipulating the first link and the second link about the axis ofarticulation, wherein manipulating the first link and the second linkabout the axis of articulation comprises sliding a plurality of slatsextending in a longitudinal direction between the first link and thesecond link against each other; and inhibiting articulation between thefirst link and the second link by inhibiting sliding of the plurality ofslats relative to each other by pressing the plurality of slats againsteach other.
 18. The method of claim 17, wherein pressing the pluralityof slats against each other comprises applying a force oriented normalto the axis of articulation to the plurality of slats.
 19. The method ofclaim 18, wherein applying a force oriented normal to the axis ofarticulation to the plurality of slats comprises applying a force withan exterior covering surrounding the body at a location of the pluralityof slats.
 20. The method of claim 19, wherein applying a force with theexterior covering comprises applying a vacuum interior to the covering.21. The method of claim 16, wherein inhibiting articulation between thefirst link and the second link comprises locking at least a portion of ashape of the segmented instrument.